This invention is directed to the field of trigger dispensers, also known as trigger sprayers. The invention is particularly directed to a trigger sprayer having structure for foaming a dispensed liquid where the structure is adapted for adjustments to vary the foam pattern of the dispensed liquid to obtain an optimum foam pattern for any particular liquid, and to the incorporation of a device integral with the sprayer nozzle housing for sealing the opening of a foam dispensing passage of the foamer trigger sprayer.
There are numerous patents that have issued on trigger dispensers of the general type to which this invention relates. The patents discussed below exemplify such trigger dispensers. Generally, a trigger dispenser of the type involved here is a relatively low-cost pump device which is held in the hand and which has a trigger operable by squeezing or pulling the fingers of the hand to pump liquid from a container and through a nozzle at the front of the dispenser.
Such trigger dispensers may have a variety of features that have become common and well-known in the industry. For example, the dispenser may be a dedicated sprayer that produces a defined spray pattern for the liquid as it is dispensed from the nozzle. It is also known to provide adjustable spray patterns such that with a single dispenser the user may select any one of several stream patterns from a stream to a fine mist. Some known trigger dispensers also include a way to seal the dispenser to prevent liquid from leaking from the nozzle orifice during shipment or non-use. A variety of sealing arrangements are known as will be more fully explained.
It is also well-known to provide trigger dispensers with a means to produce foaming of the liquid as it is dispensed from the nozzle orifice. Such trigger dispensers are generally referred to in the industry as "foamers". Typically, the foam is produced by providing a structure forward of the nozzle orifice upon which the liquid from the orifice impinges to produce turbulence, and thus foaming of the liquid and/or the added structure has openings for admitting air for entrapment by the liquid to cause the foaming. Various types of foamers are known as will be more fully described below. A common attribute of foamers is that the foam pattern they dispense is not adjustable because the structure forward of the nozzle that produces the foaming of the liquid is constructed in a fixed position from the nozzle. This is not a problem in use of known foamers because it usually is not necessary to vary foam patterns as it is spray patterns. However, in many situations to get the optimum foam pattern the position of the foaming structure relative to the nozzle orifice of a foamer is determined by the particular liquid with which the foamer is to be used. Therefore, many foamers are specifically designed for use with a particular foaming agent of the liquid with the position of the foaming structure relative to the nozzle orifice being fixed to produce the optimum foam pattern for the particular liquid. If the trigger dispenser is to be used with another liquid it may have to be reconstructed with the foaming structure repositioned relative to the nozzle orifice to obtain the optimum spray pattern for the other liquid.
Also, it is well known to provide foamers with a means for sealing the orifice to prevent leakage of the fluid from the dispenser during shipment or non-use. Examples of known foamers with sealing means are described below. As will be more fully described, the present invention is specifically directed to a trigger dispenser of the foamer type having structure for adjusting or varying the foaming pattern and to adapt the foamer for use with different foaming liquids, and with a simpler and less expensive means for sealing the dispenser from leakage during shipment or non-use.
U.S. Pat. No. 4,350,298 discloses a foamer trigger dispenser of several embodiments. A first embodiment is shown in FIGS. 1 and 2 where a hinged door may be placed in position in front of the nozzle orifice to produce a foam. No means are provided for sealing the orifice. The door positions the foaming structure at a fixed position in front of the nozzle orifice so the dispenser is not readily adaptable for use with different foaming liquids that would require the structure to be repositioned relative to the orifice to obtain an optimum foaming pattern of the liquids.
The embodiment of FIGS. 5-9 has a nozzle cap that produces foaming and where the cap is operable in a sliding or push-pull fashion. The nozzle includes a sealing member or rod which is capable of closing the nozzle orifice. By sliding the nozzle to the extended position, the dispenser operates as a foamer, and by sliding the nozzle to the retracted position the rod seals the orifice and prevents leakage. This embodiment has the advantage of a means for preventing leakage, but has the disadvantage of having a push-pull type nozzle. Nozzles that operate between open and closed positions by either a push-pull operation or a twisting or turning operation have the disadvantage that the user finds it difficult to operate the nozzle. The user may not know how to operate it at all, or may think it should be operated by turning when it should be operated by push-pull, or vice versa. This embodiment also has the disadvantages of being more complex to manufacture and of not being adapted for use with various different foaming liquids.
A third embodiment is shown in FIGS. 10-13. The nozzle cap that produces foaming is screwed to the dispenser body and operates between a sealing position and a foaming position by turning the cap. This embodiment has the disadvantage of requiring a screw cap that must be turned by the user to operate the dispenser between a closed non-leak position, and an open foaming position. As with the previous embodiment, users are often confused as how to operate a dispenser that has either a twist cap or a push-pull cap. Also, the screw cap requires molding a separate part and thereby adds to the expense of the dispenser and the cap is not adapted for use with various different foaming liquids.
U.S. Pat. No. 4,463,905 and 4,603,812 disclose a foamer trigger dispenser with a hinged door having a screen such that pivoting the door to a position in front of the nozzle orifice produces foaming, and pivoting the door so as to remove the screen from in front of a nozzle orifice produces a spray. With the dispenser of these patents the hinged door is for the purpose of selecting either the spray or foaming condition. The door positions the screen at a fixed distance in front of the nozzle orifice so the dispenser is not readily adaptable for use with different foaming liquids which would require the screen to be repositioned relative to the orifice to obtain the best foaming pattern of the liquids. While the trigger dispensers of these patents do not appear to have a means for sealing the orifice against leakage, it is known in the art to provide such a sprayer with a twist nozzle whereby the nozzle, including the hinged door, is turned between off and on positions. In the off position the liquid is prevented from reaching the orifice while in the on position the liquid is allowed to flow to the orifice. This dispenser, with a nozzle that must be rotated between seal and non-seal positions, has the same disadvantages as noted above.
U.S. Pat. No. 4,669,665 discloses a foamer nozzle which includes a cylinder extending forwardly of the nozzle orifice such that the spray from the orifice impinges on the inner cylindrical wall of the cylinder to produce turbulence, aeration, and foaming of the liquid. No sealing means are disclosed for preventing leakage. However, other trigger sprayers are known in the art that have a nozzle with a foaming cylinder extending forwardly of the nozzle in axial alignment with the nozzle. The foaming cylinder has radially extending holes at its base . The cylinder is of a diameter and length such that the spray from the orifice impinges on the inner cylindrical wall of the cylinder to produce turbulence, and such that air is drawn inwardly through the openings to mix with the turbulent spray within the cylinder to produce foaming, assuming of course that the liquid has a foaming agent. This foamer also has a means for sealing against leakage which includes a twist-type nozzle which is turned between on and off positions. In the on position liquid is allowed to pass through the orifice whereas in the off position the liquid flow to the orifice is blocked. This foamer has the same disadvantages as with the other foamers having twist or screw-type nozzles.
Other prior art patents representative of foamer trigger dispensers having foamer nozzles of the twist cap or screw cap type, or sliding push-pull type, some of which have means for sealing the orifice, are U.S. Pat. Nos. 4,730,775, 4,767,060, 4,768,717, 4,779,803, 4,883,227, 4,890,792, 4,911,361, and 4,953,791. U.S. Pat. No. 4,779,803 combines twist and push-pull operations whereby the nozzle is turned or twisted to operate it between off and spray positions, with a moveable element which slides between a retracted position where it does not influence the spray from the orifice and an extended position spaced forwardly of the nozzle orifice to modulate the spray and produce foaming, if the liquid contains a foaming ingredient. The foamer of this patent has the disadvantages of twist-type nozzle and push-pull operation as heretofore explained.
Other examples of foamer trigger dispensers are shown by Japanese Patents 63-193556, 1-110863, and 2-61456. The dispensers of these patents have an integrally hinged door with an opening in the door and a cylindrical portion surrounding the opening and extending rearwardly therefrom toward the nozzle orifice. When the door is in its closed position, the cylinder also surrounds the nozzle orifice and becomes axially aligned with the orifice such that spray from the orifice impinges on the inner cylindrical wall of the cylinder to produce foaming, the foam exiting through the opening in the hinged door. The foaming structure is not readily adaptable for optimum use with various different types of foaming liquids. While Japanese Patent 63-193556 does not show any means for sealing the orifice to prevent leakage, it is known in the prior art to provide a separate plug insert with a cylindrical portion that fits within the door cylinder. At the opposite side of the cylindrical portion is a semi-spherical element. With the cylindrical portion of the plug inserted into the door cylinder, and with the door closed, the semi-spherical element seats within the nozzle orifice to seal the orifice. The separate plug is inserted for shipping to prevent leakage, but must be removed in order to use the dispenser as a foamer.
U.S. Pat. Nos. 4,153,203, 4,230,277, and 4,815,663 and Japanese Patents 3-32758 and 57-32626 disclose trigger dispensers having a nozzle cover or door connected to the nozzle with an integrally formed hinge. The cover may be pivoted between a locked position where it is out of the way of the nozzle orifice so that liquid may be sprayed from the dispenser by operation of the trigger, and a seal position where the cover overlies the nozzle orifice to prevent liquid from leaking from the orifice such as during shipment or non-use. The cover has a central seal section with a semi-spherical portion (76/176) which seats against the nozzle orifice with the cover in the seal position to seal the orifice. While the patent discloses a desirable integrally hinged door pivotable between an operating position and a seal position, and thus overcomes the disadvantages of trigger dispensers utilizing twist or push-pull type nozzles for that purpose, there is no disclosure in the patent of any means for producing foam.
To summarize the prior art, there are foamer trigger dispensers which have pins that seat within the nozzle orifice to seal the orifice against leakage, but with such foamers the orifice and pin are moved relative to each other between sealing and non-sealing positions by either turning the nozzle or sliding the nozzle with a push-pull operation. The turning or sliding action assures that the path of movement of the pin will be restricted to an axial path within a cylinder, thereby assuring that the path of the pin will not intersect any portion of the wall of the cylinder. Thus, such foamers have the disadvantages of being confusing to operate and of not being readily adaptable for use with different types of foaming liquids as explained above. Other prior art foamers have hinged doors that may be pivoted between open and closed positions to select either spray or foam, but such foamers are not readily adapted for use with different types of foaming liquids, and either have no means at all to prevent leakage, or if they do have such means they require a separate plug which is relatively expensive and must be removed to use the foamer or require turning the nozzle with the disadvantages heretofore explained. There are also prior art trigger dispensers with hinged doors that may be pivoted between seal and non-seal positions and where the door has a semispherical element that seats in the orifice to seal the orifice with the door in the seal position. However, such dispensers are not foamers.
Thus, the prior art suggests that a seal for the nozzle orifice of a nonfoaming trigger sprayer can be on a hinged door, but the door is mounted in general vertical alignment with the orifice. However, on a trigger sprayer having a foam inducing cylinder projecting forward of the nozzle orifice, an elongated pin having an end for sealing the nozzle orifice must be moved axially within the foam inducing cylinder, or the orifice sealer must be on a separate removable element. Moreover, the foaming structure of trigger sprayers is typically constructed in a fixed position from the nozzle orifice best suited for a particular foaming liquid and to adapt the sprayer for use with another liquid the foaming structure and nozzle orifice must be reconstructed.
The present invention overcomes the disadvantages of the prior art foamers and provides a unique foamer trigger dispenser having a foam producing screen that is easily positioned at any one of a variety of different distances from the nozzle orifice best suited for the particular foaming liquid to be used with the dispenser and with means for sealing against leakage such as during shipment or non-use, which is relatively inexpensive to manufacture, and which is exceptionally easy to use.